Well, you can patent or trademark designs. And our legal system protects the holder of those patents and trademarks for good reason. Amazon is able to leverage their position in the market to abuse suppliers and get away with illegal behavior because the suppliers lack the resources to fight Amazon.

There's a difference between a clean room design that takes inspiration from a product and an identical copy. I can write and perform a song in the style of The Beatles, but I cannot write and perform "Hey Jude" without paying royalties.